Origins are tricky when it comes to heroes and villains. Mainly because they can be altered or rewritten depending on writers and how long its been since the character was created.
For Harley Quinn, she’s had a few different origins, and if a pic (that’s now deleted…but you can see it here!) is to be believed, they may be doing the one that ties her to the Joker in more ways than one.
In the pic, that was taken by Margot Robbie’s stunt double, it appears that Harley will be at Ace Chemicals at some point in the film. In one DC comic, Harley was thrown by the Joker into a vat of chemicals similar to the one he was thrown into. It caused a similar reaction, and caused her to be the Harley Quinn we now know.
Not true, they could be there for another reason, but it’s interesting to think about, isn’t it?